Integrated circuits find application in many of today's consumer electronics, such as cell phones, video cameras, portable music players, printers, computers, etc. Integrated circuits may include a combination of active devices, passive devices and their interconnections.
Passive devices such as on-chip capacitors are critical components of integrated circuits. These capacitors are used for a variety of purposes including bypass and capacitive matching to analog and radio frequency integrated circuit applications. Recently, back-end-of-line (BEOL) vertical parallel plate capacitors (VPPCAP) with stacked via and inter-digitated co-planar positive and negative horizontal metal structures have emerged as an attractive option for advanced CMOS and BiCMOS RF technologies because conventional planar capacitors such as metal-insulator-metal (MIM) capacitors require extra process steps and masks.
As today's integrated circuits become more complex, multi-level metallization technology (sometimes including more than 8 metallization layers) enables the formation of a VPPCAP structure that can be achieved without the extra process steps and masks common to other on-chip capacitor structures. However, in order to achieve the higher capacitance density (capacitance/area) so desired for these BEOL VPPCAP structures, the finger pitch of the VPPCAP structure must be designed with more and more stringent minimum pitch requirements that sometimes violate VPPCAP design rules.
Unfortunately, the progression of the minimum pitch requirement of these VPPCAP structures is causing process difficulties and long-term reliability problems, such as via protrusions that cause time dependent dielectric breakdown (TDDB) failure, which are rapidly becoming some of the most critical challenges for qualification of such capacitors.
Thus, a need still remains for a reliable integrated circuit system and method of fabrication, wherein the integrated circuit system exhibits improved capacitance density and reliability performance. In view of the ever-increasing commercial competitive pressures, increasing consumer expectations, and diminishing opportunities for meaningful product differentiation in the marketplace, it is increasingly critical that answers be found to these problems. Moreover, the ever-increasing need to save costs, improve efficiencies, and meet such competitive pressures adds even greater urgency to the critical necessity that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.